1. Field of the Invention
The present invention relates to an electronic device capable of supplying power to a card reader, and more particularly to an optimal electronic device for reducing power consumption.
2. Description of the Background Art
Currently, reduction of power consumption is generally required in electronic devices. Similarly, reduction in power consumption is also demanded in electronic devices having a card reader for IC cards or magnetic cards (for example, an image forming apparatus). Depending on the specifications of the card reader, a card reader needs to be connected by USB (Universal Serial Bus), and therefore in order to reduce the power consumption of the card reader, it is necessary to reduce the power supplied from the USB. An image forming apparatus which can be transferred to a power saving standby state in order to reduce power consumption has been disclosed in common art references.
However, when a card reader is provided in a conventional image forming apparatus via a USB connection, it is necessary for the card reader to be on (in a powered state) at all times, in order to be able to determine whether or not a card has been inserted, at all times. Therefore, even if it is possible to switch off the power source of the motor, and the like, provided in the image forming apparatus, it is not possible to switch off the power supply to the card reader. Consequently, if a card reader is provided in a conventional image forming apparatus, then it is not possible to reduce the power consumption corresponding to the card reader.
The current flowing through a card reader receiving a supply of power via a USB connection is approximately 50 mA. If the frequency of use of the card reader is low, then it is necessary to for the power supply to be on at all times for the card reader which has a low frequency of use, and this poses a problem from the viewpoint of reducing the power consumption.